Mercury-vapor-arc lamp.



BEST AVAILABLE COP` C) 0.BASTIAN 6L A.` E. SALISBURY,

MERCURY VAPOR ARC LAMP.'Y

APPLlcAUoN FILED Nov. 12, 1915.v

92041 1 1 7'. Y 'Patented Nov. 7,:1916.

'2 SHEETS-SHEET l.

C. 0.' BASTIN & A. E. SALISBURY.

MERCURY VAPOR ARC LAMP. APPLICATION man Nov. 12. 1915.

Patented Nov. 7, 1916.

2 SHEETS-SHEET 2.

w/mfss l Nro l fr - AnonNEr 'nutren srarns reruns? caricia CHRLES ORME BASTIAN AND ALBERT EDWARD SALISBURY, 0E LONDON, ENGLAND, ASSIG-NORS TO COOPER HEWITT ELECTRIC COMPANY, OF HOIBOKEN, NEW JERSEY,

A CORPORATION 0F NEW JERSEY.

MERCURY-VAPORARC LAMP.

Original application filed August 25, 1904, Serial No. 222,148.

12, 1915. Serial No. 61,169.

To all whom t may concern yBe it known that we, CHARLES ORME BAs-v 'rInN and ALBERT EDWARD SALISBURY, subjects of the King of Great Britain, and residents of London, England, have invented certain new and useful Improvements in Mercury-Vapor-Arc Lamps, of which the following is a speciicatio .f

This invention relates to electric lamps of the character known as vapor lamps or mercury vapor lamps or vapor arc lamps and .comprises an exhausted or any Iother suitable chamber for containing merarrangement and operation being lsuch that when the current is first sent through the 'lamp and through the vmercury connecting the aforesaid electrodes o r contacts thereby the mercury is automatically caused to recede or divide into separate bodies or caused to recede from one of the contacts and thereby the mercury is vaporizeil and the ar'c is struck or luminosity produced andthe length .of thearc or luminous spaceis extended or prolonged up to any practical length within the limits of the lamp.

.XVe will nowv describe our present inven-` tion (as carried into practice) with reference to the accompanying drawings as fol lows .Figure 1 is an elevation (with the case and inclosing globe shown in section) of a mercury vapor lamp constructed accordingto our present invention; said lamp being shown in position ready to` start z'. e.befoie the current is turned on. Fig. 2. is a local view of the container or vessel for holding A the mercury, etc., (which may conveniently be referred to as the burner shown de tached from the lamp-this view showing the adjustablesleeve or means for regulat- SpecificationA of Letters Patent.

Ratented Nov. 7,1916. Divided and this application lcd November ing the radiating surface of the condensing' chamber of said burner. Fig. 3 is local View showing another form of said container for holding the mercury.

Referring now to Figs. l to 3. The ex` hausted movable container or chamber for containing .the mercury (i. e. the burner consists of a tube @horizontally disposed or thercabout of cylindrical or other suitable form in cross-sectio`n and either of the saine or differing shape in cross-section` throughout itsllength and made of glass or any suitable translucent material but for the sake ofl brevity we will hereinafter refer to all such materials as vglass only, such glass tube a being provided at one end with an enlargement al or in place of such enlargement the glass tube maybe continued at this end at an angle i. e. sloping outwardly and upwardly so as to only allow the mercury to recede (nr/ be caused to runiback into same when the! tube is tilted into the position shown in Fig! 2 z'. e. when this end al is lowered or in lower position than the other end. At t e opposite end of said glass tube a to the aforesaid enlargement a?, etc., for receiving the mercury when the device is started, we provide a cross tube a2 disposed verti-- cally or thereabout, i. e. practicallyrat right angles to the, aforesaid horizontal tube a the lower part of which cross-tube a2 eX- tends below the bottoinleyehof 'the horizon` tal tube a (or be otherwise suitably arranged to retain some of the mercury) and has one of the electrodes ,located therein and in contact with themercuryin the bottom of said crosstube a2 while the upper end of the lattervmay be in connection with a condensing chamber or enlargement consisting of a glass bulb such as (t3 of a size to present a sufficient radiating surface on the one hand to enable the mercury vapor to condense sufficiently rapidly therein while on the other hand this radiation surface may be limited to prevent the mercury vapor condensing too rapidly to interferewith the proper and etlicient worlr-v ing. of the lamp; vand in actual/'practice'iwe have found thatthe radiating surface should be reduced as near as possible to Zero in order to insure tl'iermost efficient working of if" desired on or so as to operate on the core the lamp-or if any radiating chamber is provided, it may be formed as a cylinder (or of other suitable shape) and provided with an adjustable sleeve or envelop of low heat radiating capacity .by adjusting which latter more or less of said radiating surface can be covered or uncovered thus enabling adjustment of the lamp to a nicety, and the envelop may be fixed in position when the desired adjustment has been obtained.

In'the case illustrated the enlargement al at one end of the horizontal glass tube and the condensing chamber a5 at the other end of the glass tube as aforesaid are respectively mounted and held in metal caps a4 and (L5 which latter are provided with lugs or inwardly turned arms a forming contacts through and by means of which saidr glass tube is mounted in position (and the mercury therein placed in circuit) in the lamp and again readily removed from the lamp for instance said lugs or arms may simply rest in the spring clips b1 c on the de nd. g arms I) c which latter are insulated from .one another and to each of which one pole oi' the circuit is connected. These two said depending arms b c are car ried on a rock-beam d pivoted at d1 to a fixed part of the frame of the lamp in conjunction with which pivoted beam or cradle means are provided to limit the extent to which said beam can be rocked for instance beneath said pivoted beamd` we Ina-y arrange adjustable stops such as screws e by adjusting which latter thereby the extent of movement of the rock-beam d can' be regulated. To this rock-beam cl an upwardly extending arm or lever f is attached which arm at its upper end is linked at f1 to the core or armature g of a solenoid or electro magnet It which latter' is carried on al fixed part of the frame ot' the lamp for example as illustrated this magnet k may be ,fixed to a rigid bracket i which at its upper part isattached rigidly to a lug y' on the inside of the top of the frame kof the lamp whil/e the said bracket fe'. at its lower end is/icnt and turned inwardly at t" and downwardly at 'i2 to form a support for the aforesaid pivoted rock-beam d and .the aforesaid adjusting screws e. I

Z is bottom plate provided at the bottom of any suitable metal hood or casing such as: said bottom plate being provided with slots l through which the aforesaid depending arms can freelyrpass without touching; and the parts of the lamp below said bottom plate may be inclosed in a globev m of any suitable character'. j A' spring o (or weight) may be provided g in order to insure said core being forced voutoit the co1l instantly the current is inf terrupted.

j) pl are the terminals of the lamp byr condensing chamber reduced practically to' zero or as near as possible to zeroand in this case no adjustable sleeve u* or other adj ustable means are employed fr controlling the condensation of the mercury.

The operation of the lamp and burner illustrated in said Figs. 1 yto 3 is as fol`- lows :-Bei"o`re the current is switched on the aforesaid so-called horizontal glass tube a occupies the approximately horizontal position as shown inFig. l and the body of mercury e extends along said horizontal tube and covers or makes contact with the electrodes or contacts and y at each end of said horizontal glass tube.

W hen current is switched on through the lamp it iiows between the electrodes .r and y located at opposite ends of the said hori' zontal glass tube a, through the mercury z located in said glass tube a. in the position shown in Fig. l and at the same time the electro-magnet h 1s energlzed and the core g thereoi` thereby drawn up. .into said magnet.

and thus the pivoted beam d is rocked and consequently the so-called horizontal glass tube o is tilted or moved into a different position so that the mercuryis separated (at or near the point of junction of the horizontal glass tube a with the vertically disposed cross-tube o2) t-hus leaving some of the mercury in the lower part of the crosstube rz? while the general body of the mercury recedes or is caused to flow back along the horizontal glass tube into the enlargement al and thereby the arc is struck or luminosity produced and the mercury vapor formed and the lamp continues burning, and the electro-magnet hgluring the burning of the lamp continues to hold-the glass tube a inthe tilted position hs long as the current continues to How. f

The mercury vapor meantime continuously condenses in the radiating chamber a3 andthe 'condensed mercury falls from said condensing chamber toward the botjtom of the cross-.tube a2 and keeps the contact Vtherein covered and any excess of mercury rising in the cross-tube a2 above the ylevel of the tube'v ,a (at its junction with the tion nfl the current after desired variation-currentwith constant potential or the 'potential A,maybe varied ,peres when the lampjwill cury at this latter' end a1 of the said tube a, and a continuous burning lamnls thereby made possible. l t

Should the current be interrupted either momentarily or Otherwise-immediately t'he current ceases the' electro-magnet releases the core, the rock-beam 'cl is consequently rocked back and the tube 'a and connecting parts (i. e. the burner) are consequently restored to the position shown in Fig. l z'. e. to their normal position which they occupied before starting the lamp whereupon the current can flow again through the mercury between the two electrodes and contacts and upon this again taking place the lamp will be'automatically startedup agai and so on. y

With reference to all the drawlngs2-W'e find in p racticethat mercury vapor lamps constructed'according to our present inven-v tion may `require rather more current -to start them than is necessaryto keep them lighted when once the ymercury has been warmed up and vaporiz'ed. y

For example ala'mp' having a soecalled horiaontal glass tube of about four inches .in length and one-quarteror one-third of 4an inch diameter strikes-up. readily With about twol amperes but afteraboutul seconds theifcu'rrent'4 may be' reducedz to" -about 0.6 ami 3. ontinue burning steadily with the lat'rf cf I .aitmg may be eectedin any suitable Wayl; e. @by means lot a switch operating awariable resistance in series with the lamp astocontrol'the so as to vary the current inthe desired man ner by means of a 'c`hoking coil or'otherwise; or the formationof the arcfitself may bring about the desiredreductionineurrent, and in practical lworking this fis found tofbe the case.

In operatingftfwo or more of' our lamps" in series therewould be aheavyrush of -current'at thezvinstat of switching on and before the;4 cv was struck and we may if necessary, ntrol this fstarting current within thel desired. .limitsby means .of a variable resistance or by varying the potential as before described.

t. is obvious that We may control the movement of the armature within the magnet by means of, a dash-pot or in any other suitable manner or the mercury in the con tainermay be caused to give'suiiiclent L"dashpotl. action; and thls action utilized for the purpose ofsuch control.

We may-ifdesired suspend two or more of ourmercury vapor lamps on the rock* ybeam and vte may connectthese lamps sin series withfonel another or 1n parallel the `winding on the electromagnet being varied. A

This reducaccordingly. In constructing these burners we lind that leadglass is very suitable for the purpose and that pure mercury in the container exhausted to a high degree Vof vacuum gives excellent results, and under these conditions there is no tendency for the lead glass to melt or crack when the i ties of glass notably Jena glass may be used or quartz may' be used without departing from the spirit of our present invention.

The contacts or leading-.in wires or both are-advantageously made of platinum and such Wires or the contacts within the container'should always be completely covered with 'mercury except in certain cases one vsuch contatmay be exposed; for example,

one of the contacts or electrodes might be of iron or other metal but wel prefer both leading-in wires to be of platinum.

'Fromour observation' ofthe working of these lamps; apparently, during the opera.-

tion ofthe lamp, with a continuous current a transference of metal `(mercury) Atakes place from one electrode to the other (prob- 4ably a kind of. electrolytic action with metallic vapor as the electrolyte) but the loss of mercury at 4the one .electrode and the gain at the other is or may becom'pensated for by condensation or the overflowing of the mercury as aforesaid from the lastnamed electrodez e.' from'the upper electrode to lthe lower one. l i

The enlargement al (Figs. 1 to 3) in or on or at or toward the end of the container may advantageously be of an internal cai phcity or size such that it will not quite receive all the mercury out of the container and consequently it serves to limit they extent to which the mercury can be moved back' or divided and thus governs the length of the arc. or luminous space and this limitation of the size of this chainber has the further result as aforesaid that it also prevents the possibility of the` contact in the mercury in said chamber ever becoming uncovered which is a desideratum.

We would observe that we have found .that the length of the vapor arc or luminous space maybe determined or regulated not ,only by 4the angle or extent to which the y container is -tilted or moved but also by the ci'oss-sectionof the enlargement al and the size or extent of the radiating surface any variation in which latter. varies the pressure of the mercury vapor and consequently willforced back or forced apart by said pressure, unless that extent is limited by the size of the receptacle at.

The length of are is extended or prolonged up to the limits of the lamp as aforesaid; and this is controlled by means of the enlargement a* shown in sheets one and two; and when the internal cross-sectional area of the glass tube a is constant, and the angle that the latter is tilted out of the horizontal is also constant, then the length of arc will increase as the cross-sectional area of the enlargement al is increased.

When the length of the arc is controlled both by the extent of inclination of the burner and also by the pressure produced within the burnerthen with an approximately horizontally disposed tube lit is important that the latter should be in diameter about three-eighths of an inch or less so as to cause that part of'the mercury in the tube part of the burner to fill the bore at such part so that the mercury shall present a butt end or ends for the pressure to act upon, and with this object the tube (i. e. if of larger bore than ig as aforesaid) may if necessary be narrowed or restricted (fi.A e, choked) as shown for example at a7 Fig. 2.

The head of mercury producedbehind the are (2'. e. in the chamber al) by the pressure within the burner may be controlled by varying only the internal cross-sectional area of the enlargement nFig. 3 and"we do not consider it is necessary for us to state here what this cross-sectional area should be as it will vary according to the length of arc re I quired7 the pressure at which it is desired to maintain the vapor within or 'around the arc, the melting point of the translucent material around the are path and the size of the condensing or radiating chamber if the latter is provided.

In Fig we have shown one example of a burner-in full size which we have found to work excellently in practice (with 0.9 amperes) connected three in series across 200 volts with about 5() ohms, steadying resistance included in the circuit and this steadying resistance may be a carbon filament.

7e prefer to make our lamps so that the angle of inclination of the burner alone controls the length of arc and we may accordingly arrange for the mercury to run back into the enlargement al whenever the tube is tilted at the predetermined angle and if desired we may produce any necessary dashpot action which will tend to assist in governing the action of the armature so as to retard the separation of the mercury by restrictingr or narrowing the borev of the tube at any suitable point for example as shown in dotted lines at Fig. 3.

When our lamps are in operationl and when the uppermost electrode is the negative electrode we make the heat radiating surface of the ,burner as small as possible (i. e. we do not provide any special condensing or radiating chamber) but when the uppermost electrode is made the positive electrode then the loss of mercury from the electrode by transposition must be compensated for or over compensated for by providing a condensing'chamber astalreadyexplained, and without this provision in course f .75

of time the positive leading-in'wirc 'would l become exposed and the lamp thereby dam-IiA aged and we claim to be theJrst to have pointed yout the conditions under which ia'.

mercury vapor arc which is started by tilting as described can be continuously maintained in a continuous current circuit.`

If iron or other solid material is used for one electrode it is advantageous to arrange it as the negative electrode at the upper end of the lamp.

The small tubes in which the arc is formed are specially suitable and advantageous for our purpose not only because they cause the mercury to fill the bore when lying in an approximately horizontal position (which is not the case with tubes of a much bigger diameter than {5} but also because of the large light and heat radiating s irface that they present Iin proportion to their crosssection, and the importance of this fact in relation to the eiiieiency of mercury vapor lamps has not been previously pointed out and by our invention we are thereby enabled to maintain the arc in our lamps at a very We claimv as our invention z* l. A gas or vapor electric apparatus comprising a tube, a receptacle at one end of said tube and electrode material therein, another lreceptacle at the other end oi said tube and electrode material therein, and a leading-in conductor for each receptacle7 the bore ot' the tube being reduced in the neighborhood of one of the electrodes. and the receptacle at one end of the tube having an internal ea- A' pacity such that it will not quite receive all the mercury out of the tube. Y

2. A gas or vapor electric apparatus romprising an approximately horizontal tube. a receptacle at one end of said tube and electrodematerial therein. a considerable portion of the receptacle heilig above the level of'the'tube` another receptacle at the other end of said tube'and electrode material therein, and a leading-1n conductor for each receptacle, the electrode material of one ofthe receptacles' extending into a' portion of the tube Aand the bore of the vtube being reducedin the neighborhood of said freceptacle, whereby the electrode material at 'that end of the tube extends into thek receptacle andalso into the reduced portion of thevtube in the other direction, so as to form a butt end on which the pressure caused by the passage o'electric current 'in the tube lduring operation may be exerted.

3. In a gas or Vapor electric apparatus, the combination with a tubef'having a receptacle at one end and electrode materialV there in and another-receptacle at the other end thereof and electrode material therein, a leading-in conductor for each` receptacle, the

bore of the tube being reduced in the neighborhood of one of the receptacles and means for causing 'theelectrode material in the tube to vfill the bore of-the tube at the reduced portion, vwhereby the said electrode material shall producenL butt end or ends for the preS- sure of the vvapor path to act upon.

Signed at London England, this v1st day` of November 1915.

CHARLES ORME BASTIAN. ALBERT EDWARD SALISBURY.

vWitnesses:

R. WEs'rAoo'rT, FRANK J. AMES. 

